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Finding the Fourth Proportional to 289.79, 399.90 and 171.71

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Solution

The fourth proportional to 289.79, 399.90 and 171.71 is: 236.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.79 : 399.90 = 171.71 : x
  2. Step 2: Convert to fraction form
    289.79/399.90 = 171.71/x
  3. Step 3: Cross multiply
    289.79x = 399.90 × 171.71
  4. Step 4: Simplify right side
    289.79x = 68,666.83
  5. Step 5: Solve for x
    x = 68,666.83/289.79
  6. Step 6: Final answer
    x = 236.95

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.